Tonka Crash suggested:

Glow Sticks - Power free light source that times out after a reasonable time (minimum 30 minutes).  A Kerbal pulls it out of inventory, activates it through PAW menu. The Kerbal can drop it and it will keep glowing until it times out.  Defaults to a greenish-yellow glow.  Optionally, allow a slider to adjust intensity.  Duration and intensity are inversely proportional.  The brighter the glow, the faster it times out. Extra points for cleaning up behind itself.  When the timer runs out, the part deletes itself from the game instead of creating debris.